Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

vsolepr writes "Today's scheduled launch was scrubbed because of a gaseous hydrogen leak near the spacecraft's external tank. This is the fourth time in the past week that Discovery's launch was delayed due to various leaks and electrical issues. NASA now is aiming for a launch date no earlier than Nov. 30."

I think I'd be shaking in my boots if I was a Discovery bound astronaut. Although, I think it's a good thing their exhaustive checkout is finding more issues, it's a real drag to see NASA struggling to get one last launch of the Discovery and having such showstopper flaws. I understand that no amount of engineering or preparation can substitute the small amount of pure luck it is to have a successful space launch with all things considered, but you can't help but wonder if there wasn't such drastic funding cutbacks for NASA in space exploration and aeronautics if we'd be seeing a different, more positive outcome from the same reporting.

I think I'd be shaking in my boots if I was a Discovery bound astronaut.

If you didn't, then you don't understand what is happening at a launch:-)

They called the Space Shuttle most complex mechanical machine ever built (these days the Large Hadron Collider has that award). John Glenn had his famous his famous quote about his Mercury spacecraft launch: "I was thinking that the rocket had twenty thousand components, and each was made by the lowest bidder".

Is this nasa's way of playing politics? As long as they don't lunch the shuttle program isn't over. There has just recently been a power switch in government so maybe they are waited to see what will happen than. It is also possible that all of these things are happening.

I doubt it. Eleven days ago we had the 50th anniversary of a huge Russian launch accident where the ground staff were forced to continue in unsafe conditions at gunpoint. Around 126 people died including the idiot official with a gun.The possibility of the thing blowing up on the pad or later will be in the mind of everyone near it and they won't let mere politics get in the way of them doing their job like it did 50 years ago. It will go when they are ready.

More like this is a demonstration of why you don't fire a crucial employee with notice. You don't ever tell them that their job is ending after they finish with [x]. As soon as you do this, they are demotivated. They have no real motivation to do a good job because they could do a catastrophically bad job and they still wouldn't get fired.

They have no real motivation to do a good job because they could do a catastrophically bad job and they still wouldn't get fired.

I'd hate to work where you do if the only motivation you people have to do a good job is the fear of being fired.

But that's not really the problem anyway: the real problem is not that the 'crucial employees' start doing a bad job, but that once they realise they're going to be out of a job in two years the 'crucial employees' are the first ones out the door because they can easily get a new job elsewhere.

I'd hate to work where you do if the only motivation you people have to do a good job is the fear of being fired.

It's more than that. If you've ever seen a company where people are forced to train their replacements, you'd know what I'm talking about. If you know that you're about to lose your job, there's a definite sense that what you do must not be important, or else you would still be doing it.

Here we have yet another example of the Eloi hate of the greasy Moorlocks that actually do stuff other than lounge around in a garden waiting to be eaten. Have you considered that the workers in question would actually be proud of their work and watch the launch with the joy of seeing the results of a job well done?

Silly boy. They fly on big bits of metal and a lot of fuel. The accountants just want to to think they fly on money so they can inflate their importance to a greater level than the scientists, engineers and technicians that actually build the things.It's like saying Al Gore invented the internet because he provided the money. Some people actually think that way but it is a delusion.

Here we have yet another example of the Eloi hate of the greasy Moorlocks that actually do stuff other than lounge around in a garden waiting to be eaten. Have you considered that the workers in question would actually be proud of their work and watch the launch with the joy of seeing the results of a job well done?

Yep. The slacker slashdotter is incapable of imagining that any mindset but their own exists, let alone being capable of understanding it.

Have you considered that the workers in question would actually be proud of their work and watch the launch with the joy of seeing the results of a job well done?

For most of the workers, this is probably true. But it only takes one or two who have 'clocked out early' to ruin something like this.

And look at the evidence. If nothing had happened yet, you might have an argument that I'm just being overly cynical. But this thing is is leaking all over the place. After the THIRD launch scrub due to the ET l

It is out of bounds until there is evidence. Think of it along the lines of you having a child that breaks a bone and somebody immediately accusing you of child abuse without any evidence.That's what your accusation of only one or two greasy worker scum slacking off sounds like and why it is offensive, especially since many of them are very likely to have levels of education, experience and skill far beyond yourself. It's NASA and a very specialised job so some of the guys with tools have doctorates or ha

The vehicles are getting too old to fly, despite the overhauls they get after every mission. Even the disposable parts (like the tank) because of attrition in the skilled workforce that built them.

Not that we haven't known this was coming for longer than it took to go from a standing start to men walking on the Moon, but too many managers have been more concerned with protecting their turf than ensuring continued manned access to space.

Not that we haven't known this was coming for longer than it took to go from a standing start to men walking on the Moon

Except we never went from a standing start - unless you count the standing start as being around the early to mid 50's. When President Kennedy set us on the path to the moon every single major component of the Apollo program was already under development.

too many managers have been more concerned with protecting their turf than ensuring continued manned access to space.

Yep, even from a mid-50s standing start. Fifteen years to get to the Moon. We've known that we'd have to retire the Shuttles for almost 25 years, when the replacement for Challenger was built partly using long-lead-time spares that were not replaced.

When program managers wail to their congresscritters about how many jobs will be "lost", guess where said congresscritters decide to devote funds. Do most congress people know much about space technology development? No. Who are they going to listen to? T

Yep, even from a mid-50s standing start. Fifteen years to get to the Moon. We've known that we'd have to retire the Shuttles for almost 25 years, when the replacement for Challenger was built partly using long-lead-time spares that were not replaced.

*yawn* You're powers of mathematics are impressive. Your actual knowledge of the world, much less so. (Short version: you're an idiot. We knew the Shuttle would eventually retire before we even started building them.)

HOTOL might have been more cost-effective. The Russian space shuttle almost certainly would have been. The problem with the space shuttle was that false economies were made. Sometimes to save money you have to spend it. The shuttle was under-sized, under-powered and was forced to have dangerous piecemeal boosters for political reasons. By spending the money up-front, you'd have a cheaper, safer, more reliable shuttle which would doubtless still be in production, not scrapped.

Air-breathing engines are heavy and require you to fly... in air... which means very high drag and very high fuel consumption. Unless you can build some kind of dual-mode jet/rocket like Skylon, or build a jet-powered first stage and a rocket-powered second stage, you're better off just forgetting about them.

There's a reason why rockets go pretty much straight up at the beginning of a launch: they want to spend as little time as possible at high speed in the atmosphere to eliminate drag losses and make the

I'm not in disagreement with you, but I still am really interested in knowing how much of the "cost" of launching a shuttle is amortized into the space program's sunk costs, how much is in the market value of natural resources, how much is in salaries and real estate expenses and stuff, and how much is marginal costs... Not just "how much", but "who gets the money" and "for what?"

I have no doubt the program could have been far more efficient. But given the non-negotiable parameters of the shuttle as it wi

I'm not in disagreement with you, but I still am really interested in knowing how much of the "cost" of launching a shuttle is amortized into the space program's sunk costs, how much is in the market value of natural resources, how much is in salaries and real estate expenses and stuff, and how much is marginal costs...

It's a few years since I looked into this, but I believe at the time the variable cost of a shuttle flight was around $250,000,000 and the fixed costs of the program were over $3,000,000,000 a year. A lot of those fixed costs go into maintaining KSC and other NASA facilities; imagine how much an airline ticket would cost if you flew a mere six times a year and did so from your own multi-runway international airport with a staff of thousands.

Though I sometimes wonder what attaching, say, two large turbofans could give; as a "zero" stage of sorts. Widely available (though not with afterburners, which would be good here), well understood, reliable, many rockets use the same fuel (though, considering the complexity & weight of plumbing plus small amount the turbofan would use, it's most likely better to integrate small tank in "booster module"), large thrust-to-mass of such module...

NASA is investigating the use of turbine-assisted ramjets to do exactly what you're describing, and essentially what you are describing is what White Knight is for Space Ship 1. So it is being done and it is being discussed for much larger systems.

You are correct that the top altitude is 20km, but you must consider that rocket nozzles above a relatively small diameter become unstable (with a nasty propensity to explode), that you don't need to carry oxygen with you (which is bloody heavy) and that jets are

Energia would be probably nice, yes, in launches without Buran (but still probably not very cost effective due to scale and rarity of the launches). HOTOL was apparently dropped when it became clear that a rocket using the same technological advances would be at least equally effective (but much less complex). And you would want to up the size of the Shuttle?

An orbital launcher flies most of its mission outside the atmosphere. Most of its mass is reaction mass. That, together with what the rocket equation i

HOTOL was dropped by Government orders and classified. If it were really that inefficient, I don't thing Maggie's minions would have gone to such lengths.

NASA's spaceplane designs in the 1990s followed essentially the same design and was abandoned through sharp funding cuts. NASA would have had access to BaE's work on HOTOL - if the design didn't work, they would not have followed the same approach.

HOTOL may well have had insurmountable technical problems. (The last time Britain tried to develop space techn

I would rather waste money on this than some of the other crazy things that the government wastes money on. Have you ever seen a shuttle launch. It lights up the sky from 90 miles away. It is kind of impressive what humans kind can do when they are not fighting against each other.

More important than the abstract idea of what it costs to launch the shuttle, is "who gets the money?" and "for what?"

I have a feeling that if we actually *had* to put a shuttle up, and managed to keep things like corporate profits, individual compensation, and natural resource market costs out of the equation, it would be a lot less.

Absolutely. But there is a world of difference between competing in a noble competition to be the first in space, vs the competition for wealth and power that is unconstrained by any sort of moral compass.

I am all for competition, but thing there should be some like drawn between just and unjust competition. Competing by creating a better product is good. Competing by creating a patent pool and suing anyone that makes a better product is unacceptable and cowardly.

project orion wasnt really a good idea. what you really need is something more like NERVA for the upper stage, or some sort of nuclear reactor powered ion engine. like a scaled up VASIMR for in space travel.

It always puzzles me why folks imagine saying a given piece of tech is old is axiomatically equivalent to saying it's been mightily improved upon since then.

Has the pencil been improved on yet? How about the wheel? Are we still burning gasoline in cylinders with pistons to power cars, like we started doing in the 1880s? Do we still use propellors to make boats move? Et cetera.

I'm not suggesting it's not possible to improve the Shuttle -- but that case has to be made in detail, not tossed off with an assumption that because it was designed in the 60s and built in the 70s there must be a far better idea. After all, the biggest advances since the 70s have mostly been in stuff like electronics or avionics, and besides the fact that this doesn't do squat for things like thermal protection and reliability of very high energy rocket systems under very heavy load (the two weaknesses that killed Columbia and Challenger, respectively) the best of these advances in electronics have in many cases been retrofitted into the Shuttle anyway.

Point me to a genuine major advance in airframe materials, thermal protection systems, or rocket engine design since the 1970s and maybe this contempt might be better supported by actual evidence.

Unless something was not the best idea in the first place, and even worse implementation (did the Shuttle deliver on any of its main points, as advertised?)

60s, 70s...its designers probably raised on scifi with a whole lot of spaceplanes - no doubt influenced by huge airplane advances in the 40s. Which differed quite a lot from those 130 year old depiction of "our" times [goo.gl] (/. & links with unicode...), apparently influenced by rapid advances in (sub?)marine technology. We can build them (take a Harrier, remove wings and canopy), but it doesn't make those past dreams a good idea. Not a lot flying boats around nowadays, too.

Point me to a genuine major advance in airframe materials, thermal protection systems, or rocket engine design since the 1970s and maybe this contempt might be better supported by actual evidence.

That's a very valid point, most people don't realize that there never will be any "magic" improvements in rocketry to bring the cost down to the point that we'll all be taking holidays on Mars. It's still a high-energy problem, and new technology doesn't necessarily make the hard problems much easier.

There have been improvements though, they're just not that big or visible. For example, computer-aided design would allow a new rocket to be extensively modeled without expensive testing. Multiple design and testing iterations could be performed without ever stepping into a machine shop. This in turn allows design simplifications, a reduction in part counts, etc...

Computer-aided machining has made enormous improvements since the seventies, in part complexity, cost, precision, and the type of materials that can be used. Old designs would not have assumed the availability of CAM, so they might rely on manual steps, such as welding and riveting. To use parts made automatically by machines, a design optimized for that manufacturing process is required.

There have been significant materials-science advancements, which is why both Boeing and Airbus are now creating aircraft made of composites, which wasn't practical or cost-effective in the 70s. Of course, some of these advancements have made it into the shuttle, for example the Super Leightweight Tank [wikipedia.org] is made of a high-tech aluminium-lithium alloy. That's an easy part to replace, but upgrading the orbiter would be essentially a redesign, so it has remained relatively unchanged.

The real problem with the shuttle is that the fundamental concept is flawed. It assumes that people are needed in orbit -- robots do a better job now, thanks to advancements in digital electronics. In turn, the original design also assumed that it's worth reusing the container for those people. If there are no people, nothing needs to be reused. The engines might be worth bringing back down, but a small ablative heat-shield and a parachute is more than enough for that, there's no need to build a huge heat-shielded structure with wings and avionics! When it costs $thousands per kg of material sent into orbit, anything not directly serving the purpose at hand is just waste. The orbiter weighs 68,585 kg empty, of which only 9,531 kg is the engines! Not counting the structure required to protect the payload, the remaining 50 tons of shuttle structure is just a huge waste of money. That 50 tons could be payload on every launch. Over the 100+ launches that have occurred, that's 5000 tons of satellites or space probes that could have been launched. A large satellite is 5 tons, so that's over a thousand that could have gone up, but didn't. Just imagine: if only 10% of those were for solar system exploration, we could have had a hundred or more additional space probes out there among the planets!

That's a very valid point, most people don't realize that there never will be any "magic" improvements in rocketry to bring the cost down to the point that we'll all be taking holidays on Mars. It's still a high-energy problem, and new technology doesn't necessarily make the hard problems much easier.

The ultimate limit on the cost of getting into orbit is the cost of rocket fuel, which is not a lot. What is needed is reliable, reusable launchers which don't require months of maintenance by thousands of people between flights, and that's perfectly possibly with enough engineering effort... the idea that it will 'never' happen is just silly.

If there are no people, nothing needs to be reused.

So we should build single-use container ships and sink them after they've crossed the ocean once?

Reusability is _the_ biggest cost-saver possible, so long as it doesn'

That's a very valid point, most people don't realize that there never will be any "magic" improvements in rocketry to bring the cost down to the point that we'll all be taking holidays on Mars. It's still a high-energy problem, and new technology doesn't necessarily make the hard problems much easier.

The ultimate limit on the cost of getting into orbit is the cost of rocket fuel, which is not a lot. What is needed is reliable, reusable launchers which don't require months of maintenance by thousands of people between flights, and that's perfectly possibly with enough engineering effort... the idea that it will 'never' happen is just silly.

If there are no people, nothing needs to be reused.

So we should build single-use container ships and sink them after they've crossed the ocean once?

Reusability is _the_ biggest cost-saver possible, so long as it doesn't require the massive maintenance that a shuttle does between flights (not to mention the cost and complexity of the external tank and boosters).

You can't re-use the rocket fuel, and it makes up the bulk of all rockets, by both mass and volume. It is also necessarily much heavier than the payload. (think: rocket equation)

In contrast, a container ship is mostly metal, with only a small fuel fraction, and a high payload fraction.

The cost computations wildly are different, by several orders of magnitude.

None of this will change, ever, with chemical rockets for fundamental reasons. We'd need to invent entirely different propulsion systems (nuclear, fusi

I'm not sure if even nuclear would make much of a difference, assuming technologies practical for surface-to-LEO launchers(*). Saturn V with NERVA upper stage would launch 2-3 times more to LEO - certainly noticeably more, but still within an order of magnitude; and, IIRC, while nuclear thermal rockets like NERVA have 2x higher specific impulse from chemical, their max thrust is limited (so pretty much restricted to that upper stage role)The above requiring much more strict care during launch procedures. Pr

What is needed is reliable, reusable launchers which don't require months of maintenance by thousands of people between flights, and that's perfectly possibly with enough engineering effort... the idea that it will 'never' happen is just silly.

Balancing yourself on a giant tower of explosively combusting gas is never going to be particularly safe; hence the high maintenance costs to quadruple-ensure everything is "just right", before committing to what could very easily become a human fireworks display.

What's really needed is a reliable way to get high volumes of material into orbit -- one that doesn't require fuel to be present in the vehicle (other than possibly as payload). The problem with putting fuel in the vehicle is that it adds to the weight of the vehicle, which means you have to add more fuel to help lift the fuel you've already added, and so on, until the snowball effect limits the size and capacity of your vehicle to "not very much".

Once that's solved, and we can get significant amounts of material out of this nasty gravity well inexpensively, the rest is cake. Until then, it's doubtful that any rocket design, no matter how advanced, can do much -- it's like trying to empty the ocean with a teaspoon.

well actully, the high maintainence costs of the shuttle were due to everything *needing* to be quadruple checked because there wasnt a effective crew escape system, like you had on the saturn rockets. and the engines that were machined to such fine tolerances that they needed to be pretty much pulled apart and inspected for cracks after every mission. and the enormous shuttle heat shield, with tens of thousands of tiles that had to be individually inspected.

Just take one look at the thing. Great big rockets strapped onto the SIDE. That was the highly undesirable outcome of having to meet a variety of constraints that were not there when the original plans were made. They could have built a far better shuttle for specific tasks in the 1970s, but the compromises produced what we have. It shows how amazing the NASA guys are that it managed to work at all.The main factors that made it like this were a requirement to be able to get into orbits that require a lo

IIRC it never went into polar orbit. Which, by itself, doesn't require such suboptimal vehicle anyway - returning to the area of start after one or two orbits (supposedly important in military scenario...), high crossrange capability, does.

Never used of course. But it and general insistence on large winged spacecraft causes a waste of ~70 tons of LEO capability on each mission / necessity to use needlessly huge rocket (and more than 7 lives lost...)

Yes, but there are 7 lives lost that can be traced back directly to parts required to have the configuration of rockets strapped on the side. Even then it was really a long chain of events from there to ignoring warnings about the seals. I don't think a more conventional shape would have helped with the other accidents and near misses.Thanks for the correction of "returning to the area of start after one or two orbits (supposedly important in military scenario...)" because I'd forgotten that was the speci

Seems you focus on Challenger. But Columbia accident was also caused by that unfortunate side configuration, size, reliance on wings to have the required crossrange (which seem to be present in most early concepts, not really a case of changes?), etc. Without those, the specific mode of failure doesn't really exist.

yep per day that would gain me a 20 oz beer a day, something I cant afford right now, in a single income household, where I am reminded every single day by management that I am privileged to hold my pissant box monkey job even though I hold a masters in CS

nope dont help me, lets spend 1.47$ a day for over a month to what? install a storage shed so we can watch cockroaches mate in zero grav?... fuck that

One estimate in 2007 put the cost of the Iraq war as high as $720M a day. Watching cockroaches mate in zero gravity, or "bringing democracy" to a region that isn't culturally ready for it and is costing thousands of lives on top of that... I know what I'd cut first.

(Yes I know focus has shifted to Afghanistan and doesn't cost as much money, the point remains)